Software Engineer (.NET) - Madrid or Paris or Bordeaux

About Sinch

Sinch is pioneering the way the world communicates. More than 150,000 businesses — including Google, Uber, PayPal, Visa, Tinder, and many others — rely on Sinch’s Customer Communications Cloud to power engaging customer experiences through mobile messaging, voice, and email. 

Whether you need to verify users or craft omnichannel campaigns, Sinch makes it easy. Our AI-infused Super Network, APIs, and applications ensure you can connect with your customers reliably and securely, at every step of their journey. 

At Sinch we “Dream Big”, “Win Together”, “Keep it simple”, and “Make it Happen”. These values are our foundation! 

Description

As a developer, you’ll work closely with other engineers and you are an important part of creating SDKs that enable our customer developers to be productive and successful using our products: we want our customers to be successful effortlessly. Here you will have a great opportunity to write code used directly by other developers as the end users.

We are looking for a skilled .NET Developer, with a modern and curious mindset, to join our Developer Experience (DX) team. In this role, you’ll be responsible for designing, developing, and maintaining a high-quality .NET SDK that wraps our REST APIs.

You understand the importance of creating well documented and tested SDK APIs for software services. You care about what makes a good SDK experience, and what is developer friendly. You are a developer who likes to stand up for your own opinions and have the courage to speak up. You feel empathy and understand that products may be complicated for new customers and your passion is to make it as easy as possible for your fellow developer.

This role is open to candidates based in Spain or France, with the flexibility to work fully remotely or from one of our offices in Madrid, Paris, or Bordeaux.

As a Software Engineer, you will:

• Be the primary developer on the SDK/Library you are responsible for, through the whole development cycle: design, develop, and maintain a modern, user-friendly .NET SDK.
• You will be working closely with your Developer Experience colleagues on SDK features
• Ensure the SDK is well-documented, easy to use, and follows best practices for .NET development.
• Write clean, efficient, and maintainable C# code, with a focus on developer experience.
• Implement robust error handling, logging, and testing to ensure reliability.
• Optimize SDK performance and usability, gathering feedback from internal and external developers.
• You will work with the documentation team to keep all documentation easy to read, test, and add content to engage our customers.
• Stay up-to-date with the latest .NET features and industry trends.

Requirements

• 3+ years of professional experience in .NET development
• Strong understanding of REST API design and consumption
• Proficiency with NuGet package creation and maintenance
• Knowledge of CI/CD pipelines
• Fluent English
• Being able to help create and drive development and performance metrics against OKRs
• For remote work: A stable, high-speed internet connection and a dedicated, quiet workspace

Nice to have

• Experience in SDK or library development is a strong plus
• Familiarity with asynchronous programming, dependency injection, and modern C# features
• Knowledge of Python and TypeScript is an added value
• Knowledge of Java and interest in expanding your skills in this area is very welcome
• Excellent problem-solving skills and attention to detail
• Ability to communicate well in the user documentation and code

Our Hiring Process

We are committed to ensuring a recruitment process that is fair, objective, consistent, and inclusive. Our approach includes structured, competency-based interviews designed to evaluate your skills, experience, and qualifications relevant to the role. At times, we may include a data-driven assessment to enhance our hiring success and identify candidates likely to excel. 

We believe in a two-way process and encourage you to ask questions throughout the journey.  If this role isn't what you're looking for, please explore the other opportunities listed on our career page: https://www.sinch.com/careers/. No matter who you are, we hope you find an exciting path forward - hopefully with us! 

Please send your CV in English language.